Centrifugal governor



Dec. 30, 1941. A. c. HOOF 1 2,267,919

CENTRIFUGAL GOVERNOR Filed Dec. 13, 1939 3 Sheets-Sheet l TrORNEY.

Dec. 30, 1941. A. c HQOF CENTRIFUGAL GOVERNOR Filed Dec. 13, 1939 I 3Sheets-Sheet 2 IHIHH INVENTOR. WM Cfiaof @yz/m A TTORNEY-i Dec. 30,1941.

A. c. HOOF GENTRIFUGAL (:JOVERNOR Filed Dec. 13, 1959 3 Sheets-Sheet s/1I:I VENTOR.

M50 CJyOOf m1 m ATTORNEY? Patented Demo, 1941 Application December 13,1939, Serial No. 308,979

14 Claims; (01. 264-15) The present invention relates to a governordevice for controlling the speed of operation of an engine and moreparticularly relates to a governor of the centrifugal type-forcontrolling the flow of a'fiuidafuelto the engine for maintaining aconstant, predeterminedspeed of operation.

In general, devices of the instant class operate by imposing theresultants of a centrifugal force upon a yieldable, resisting means insuch a manner that the resulting movement of the parts may be employedto correspondingly shift a fuel supply valve to maintain the enginespeed constant, regardless of variation in load. The present inventionmore particularly contemplates a novel combination of centrifugal meansand yielding means wherein the centrifugal resultants are imposeduponrthe spring in such a manner sultants are imposed upon the freeextremity of the spring, as taught by the Krebs et al. patent.

as to more nearly meet the fundamental requirements 'of a centrifugalgovernor. In other words, the alteration of spring'characteristics withrespect 'to the centrifugal force resultants, as theoreticallyunderstood, is a requirement not inherent in theprior fly ball governorspring arrangements with which I have been hitherto familiar.

It is, therefore, an important object of the present invention toprovide an improved means for resisting the centrifugal force resultantsin. accordance with the practical and theoretical requirements foraccurate control of engine speed.

The present invention more particularly contemplates the attainment ofthe foregoing objects by the use of a cantilever spring of the typedescribed in United States Patent No. 1,324,198, granted December 9,1919, to Krebs et al.

of spring, to-wit: the fact that its deflection rate varies, in general,according to the cube of its length making it desirable for use invariable speed governors. In other words, since the resultants of thecentrifugal forces of the fly ball, unit vary as the square of the speedof rotation, a corresponding wide range ofvariability of spring tensionisnecessary to render the governor operable to control speeds over anyreasonable range.- In accordance'with theKrebs construction, it ismerely necessary to alter the effective length of the spring t3,amoderate range to render the device adjustable for all practical speedranges. Thus fgor example, to provide a This 5 patent describes oneimportant result of this type centrifugal force resultants as the It hasbeen found, however, that limitations of space and considerations offriction aswell as spring stresses and characteristics prevent the fullrealization of the theoretical advantages of the structure described inthe patent. Thus difiie culties have been experienced due to the practixcal limitations on the minimum size of the spring imposed by the fiexurenecessary to control the engine over a reasonable range of valvepositions and further, in view of the undesirable changes in Springcharacteristics which occur as the result of variation in angle ofapplication of the spring flexes through an appreciable arc. I

The foregoing and other difliculties are inherent in the type ofstructure wherein the spring deflecting forces are applied at all timesto the end of the spring in a suitable link. n J

The present invention has for its object to obviate the foregoingdisadvantages and, in particular, to make possible a wide range ofadjustment in a compact unit by imposing the centrifugal forceresultants on the spring in such -a manner as to relativelyrapidly-increase the effective resistance of the spring as the partsmove toward the position of maximum spring.

loading. In other words, the present invention contemplates therelatively sharp increase value of the spring tension so as to renderpermissible the use of a shorter and lighter spring than was heretoforestructurally necessary in practical use.

A further important object of'the present in vention contemplates thecontrolled imposition of speed range of from 1,000 R. P. M. to 2,000

R. P. M., it is only necessary to, alter the effective lengthgof thespring from a ratio of .approxi-,

mately 1.58 to l where the centrifugal force rethe centrifugal forceresultants on the spring in such a manner that the increase in springresist ance is somewhat disproportionate to the deflection and inparticular comprehends the correlation of the said disproportionateincrease in such a manner as to makepossible conformance ofspringloading and centrifugal force resultants" with the minimum speedvariation throughoutthe governing range of the load.

A yet further object of the present invention contemplates the privisionof an auxiliary ad j ustment means cooperative with the adjustment meanswhich determines the effective length of the spring, which auxiliaryadjustment maybe employed to vary the foregoing conformations of springloading and centrifugal force resultants in such a manner as to control.the sharpness of governor action and thus confer stability of operation;

Yet other and further objects and advantages will be apparent from aconsideration of the foregoing detailed description when taken inconnection with the accompanying drawings, wherein:

Fig. 1 is an elevational view more or less diagrammatically illustratingthe operating disposition upon an engine of a governor embodying theprinciples of the present invention.

Fig. 2 is an elevational view of the governor shown in Fig. 1, portionsof the side wall having been broken away to show the construction of thegovernor parts.

Fig. 3 is a plan view of the governor shown in Fig. 2 with the coverremoved.

Fig. 4 is a view taken on the line 4-4 of Fig. 3, b showing the parts ofthe governor in one position taken when the governor is in control ofthe engine.

Fig. 5 is a detailed sectional view taken on line 5-5 of Fig. 2.

Fig. 6 is a detailed view taken on the line 6- of Fig. 2.

Fig. 7 is a view of the parts making up the adjustable bell crank leverand roller follower assembly, the parts being shown in perspective inspaced relationship to indicate their individual construction.

- Fig. 8 is a perspective view of the spring mounting elements, theparts being similarly shown in spaced relationship to indicate theirindividual construction.

Fig. 9 is a chart showing the characteristics of the spring loading andcentrifugal force re- 7 sultants in the present governor.

The governor shown in the drawings, for the purpose of illustrating oneembodiment of the present invention, is designated by numeral Ill inFig. 1 and is operatively disposed adjacent the intake conduit l2 of anengine l4 for controlling the location of a fuel valve I 6. It will benoted that the fuel valve 16 is located in the conduit between theintake manifold l8 and the carburetor 20.

As noted above, the present invention concerns particularly a novelmeans for imposing resultants of centrifugal forces on a resilient,yieldable spring for determining the position of the valve 16. Thecentrifugal and yielding structures are enclosed within the housing [0and it will be understood that the valve I6 is connected in a suitablemanner to control shaft 22 emanating from the housing Ill.

The structure of the unit Ill, shown more clearly in Figs. 2 to 6,includes an outer housing 24 having opposed end walls 26 and 28journaling a longitudinally extending shaft 30 in anti-friction bearings32. It will be noted that the left-hand end of the shaft 30, as viewedin Fig. 4, connects with a flexible drive shaft 34 through the agency ofa coupling 36, the flexible drive shaft being enclosed within a suitablearmor or protective sheathing 38 engaging at its extremity in bushing4|] permanently sepresent embodiment it will be seen that the flexibleshaft 34 is indirectly, driven from the engine shaft.

The shaft 30 interiorly of the housing mounts a so-called fly ball orcentrifugal governor mechanism comprising a collar 44 pinned to theshaft though positively,

30 as at 46 and having integral, opposed, projecting arms 48 whichsupport at their outer extremities a pair of pivot pins 50. A pair ofsocalled fly balls or weights 52 integral with bell crank arms 54 arerotatably mounted on the pivots 50.

56 bearing against a collar 58 on the end of sleeve 60 which is slidableaxially of shaft 30. It will be quite obvious from-the foregoing that asthe weights 52 are moved outwardly under the influence of centrifugalforce as the shaft 30 rotates, the opposite extremities of the bellcrank levers 54 urge the collar 58 and its associated sleeve to theright along the shaft 30, as seen in Figs. 2 and 4.

The opposite extremity of the sleeve 60,

mounts a thrust bearing 62 for application of the centrifugal forceresultants against a lever 64. The lever 64 forms a part of anadjustable bell crank lever system, to be hereinafter more fullydescribed, and pivoted upon a transverse shaft '22 journaled in opposedlugs or embossments 68 formed in either side of the housing 24. As shownmore clearly in Fig. '7, a lever member 64 comprises two spaced sectionshaving at their thrust bearing contacting extremities spherical insertsI0 and spaced by a transverse connecting lug 12 having mounted thereinan adjustable abutment or stop abutment 14. The stop comprises merely athreaded stud or set screw threadedly traversing the flange or lug l2and carrying a lock nut I6. The abutment screw 14 normally bears againstthe upper surface of the second pivoted arm or lever of the adjustablebell crank designated by the reference numeral 11 of the drawings andbearing at its end a roller follower 18 journaled in opposed,anti-friction bearings 80.

The opposite extremity 82 of lever 16 is likewise pivotal on shaft 22.The two relatively movable arms of the bell crank assembly are normal-1y maintained in the relative position shown in Figs. 2 and 4 by acantilever leaf spring assembly 84 mounted in the lower portion of thehousing, as clearly shown in Figs. 2 to 6, by means including the partsshown in Fig. 8. It is particularly to be noted that the leaf comprisesa series of superposed spring leafs, each of the successively lowerleafs being spaced at increased distance from the free extremity of thespring. The spring leafs thus formed are mounted upon an insert withinthe housing, which insert or frame is designated by the referencenumeral 86 and permanentlyfastened by means not fully disclosed in theposition shown in Figs. 2 and 4. As shown more in detail in Figs. 2, 4,5, 6 and 8, the lower surface of the frame or partition 86 mounts aclamping block 88 bifurcated throughout most of its length to provideopposed spring embracing walls 90 integrally connected at the left handend, as viewed in Fig. 8, by an abutment portion 92. r

The block just above the abutment portion 92 is slotted as at 94 toreceive the bundle of spring leafs; The block with the spring bundlemounted therein is clamped to the frame 86 by a lower attachment block96 provided with an inclined slot 98 which cooperates with acomplementary .slot I00 within the frame member 86 to receive therectangular marginal boundaries of the block 88. Machine screws I02extend through the block 96, as clearly shown in Figs. 2 and 4, topermanently clampingly associate the parts and it will be noted that theupper sufrace of the Bell cranks 54 are recessed at their. innerextremities to receive anti-friction balls 1 frame 86 is providedwithinclined or milled slots I84 to facilitate application in the tighteningof the fastener.

' Attention is moreover directed to the fact that the present springassembly is provided with a spring bearing block I84 slidablelongitudinally in the guideway between the two spaced guide walls 98 ofthe block 88 and accordingly just beneath the lowermost leaf of thecontilever spring 84. The. bearing block I85 is movable in response tothe threaded control bar I88 received tion 82 of the block 88. Asclearly shown in Figs.

2 and 4, the slotted head H8 is permanently pinned to the control barI86 as indicated at I I2. It will be obvious from the foregoing that theeffective length of the cantilever spring may be adjusted to anypredetermined value merely by rotational adjustment of the slotted head8 to slide the bearing block I85 longitudinally of the spring.Accordingly, as the bearing block I85 -moves to the right, as viewed inFig. 2, the deflection rate of the spring decreases, whereas From theforegoing it will be understood that the present invention contemplatesthe constant rotational actuationof the shaft 38 and accordingly thecentrlfugally responsive assembly inmitted.

position of the centrifugal force resultants upon the spring 84.

Particular attention is directed to the as the lever roller deflects thespring there are three factors which progressively tend to increase thespring resistance.

deflection of the cantilever spring per unit load is proportionate tothe cube of the effective length. In the second place, the deflection ofa cantilever spring isdiminished if two or more of the top leaves are ofequal length. While the present spring following the necessities forideal design has evenly graduated leaves, nevertheless the roller, inmoving to the left, progressivefact that 7 First of all, the

ly reaches a point or points wherein the topleaves have the sameeffective length. -In other words, the roller, in moving to the left,brings the point of force application ultimately to positions where twoor more leaves lie in contiguity.

As a further factor, it will be noted that the moment of the imposedforce about the point of support of the spring is reduced as the rollermoves inwardly. Accordingly,as the roller travels inwardly from the freeend of the spring, the resistance of the spring not only increases, butdoes so in accordance with a characteristic plan which is particularlyfavorable tothe operation of the centrifugal governor of the presentclass. Moreover, these factors permit the desired variation in springresistance with a minimum of spring deflection to the end that a new andimproved compactness of design is per- That is to say, the presentinvention permits the use of a lighter and smaller cantilever spring.

This will be readily apparentfr'om a consideracluding the weights 52 ata speed equal to or corresponding to the rotational speed of the engineI4... The centrifugal force set up by the weights 52 is applied throughthe agency of lever extremities 56 to the sleeve 88 and the bell cranklever assembly 64 and I8. The forces thus created by the action of thecentrifugal weights are imposed upon the cantilever spring 84 throughthe agency of the roller follower "I8 which, as clearly shown in Figs. 2and 4, rides directly upon the upper leaf of the cantilever tion II 4 inthe frame 86. Thus it should be para ticularly noted that with the partsin normal position, as shown in Fig. 2, the roller follower I8 residesadjacent the outer-most limit or extrem ity of. the cantilever spring,where the resisting spring tension is relatively minor. As thecenmensions of the structure are thespring length.

trifugal weights, however, come intoaction to limiting speed of theengine, or, in other words,

the rotational shifting of the center of the roller follower I8 hasresulted in movement of the roller inwardly beyond the free extremity ofthe spring, thus, in effect: shortening the effective length of thespring, decreasing the deflection rate, and accordingly rapidlyincreasing or build- I ing up the rate of spring resistance.

-It will be apparent that the position of the unbalancedvalve I8 isdetermined by .the angular position of the shaft 22-, which shaft, in

" turn, is determined in accordance with the imas they approach theposition shown in Fig. 4,

tion of the chart of Fig. 9 wherein the curve H indicates the springcharacteristicsof a cantilever spring loaded at the extremity inaccordance with the teaching of the foregoing Krebs patent. Inaccordance with the chart, it will be evident that the coordinatesrepresent the angular movement of the flyweights plotted againstthe'corresponding spring tensionexerted and expressed in terms of thetorque transmitted to the crank pivot. The curve C shows the comparativecharacteristics of the same spring withthe centrifugal force resultantsapplied by means of the bell crank lever hereinbefore described.

Thus the load curve of the latter spring assembly is 40 per cent higherat maximum deflection.

than where the load is imposedat the spring. 1

It should be particularly noted that this is an important considerationin the present art where the available space is limited and the over-alldidetermined by the end of It should furthermore be noted, as pointedout above, that the spring load curve, in accordance with the presentinvention, rises at an increalsing rate as maximum deflection isapproached, in a manner which is particularly adapted to meet;

the demands of centrifugal. governor construction. Thus, it has beenfound that in order to avoid instability of governing action it isnecessary to assure a no-load speed slightly in excess of the full-loadspeed. To meet this .condition the'spring load force must at no-loadposition be slightly in excess of the resultants of the centrifugalforces which would be imposed on the spring if the no-load speed werethe same as the full-load speed.i ,So, also, the amount of unbalance orvariation between the spring resistance and theeentrifugalfiree imposedat unv 'with a minimum stabilization factor.

varying speed may advantageously increase more rapidly as the no-loadposition of the mechanism is approached for the reason that frictionalresistance, which is one of the prime causes of hunting, surging, orother instability of the gov-- in the art that since uniform incrementsof valve movement result in non-uniformvariations of developed power, itis thus ordinarily necessary to provide for a more rapid movement of thegovernor throttle valve with respect to the movement of the fly weights,in the nearly-open range of throttle than in the nearly-closed range.But if at the open, or substantially open range of throttle movement thegovernor is nearly isochronous, relative movement of the fly weights andthrottle valve are not of great significance. As is known in the art,isochronism is the result of conformance of the resultants of thecentrifugal force with the spring resistance for all throttle positionsat a fixed and unvarying speed.

In accordance with the present invention, the centrifugal forceresultants are imposed upon the spring in accordance with the foregoingprinciples. Thus, referring to Fig. 9 01' the drawings, curves A, C andH are spring loading curves for springs constructed as shown in theforegoing drawings, the curves being taken for various governed enginespeeds and over a range of fly weight movement equivalent to thenecessary range of movement of the throttle valve. curve A representsthe spring loading character- Thus tention to the improved resultsavailable through use of the adjustable bell crank lever assemblydesignated by reference numerals-64 and 16 in including the adjustableset or stop screw 14 for varying the angular spacing of the two arms ofthe lever. Thus the main adjustment means represented by the shiftablespring support I04 merely varies the effective length of the spring forcausing a corresponding variation in the load carrying rate for a givendefiectionf On the other hand, as the effective length of the spring isdiminished by this means, the spring in becoming shorter provides arelatively sharper increase in load carrying rate. In other words, asthe length of the spring decreases, the rate of change in springresistance may tend to become somewhat in excess of requirements,particularly at high governed speed ranges and particularly if a highdegree of accuracy is required at such high governed speeds. For thisreason it is desirable to control the relative characteristics of thespring and centrifugal resultants as mutually opposed. Attention isdirected to the fact that this factor, is under complete control inaccordance with the principles of the present invention.

Thus, referring again to Fig. 9, it will be noted that the dotted linecurves B, D, and F, for example, show the centrifugal force resultantsfor the isochronous condition. On the other hand, the solid line curvesrepresent the spring loading at various corresponding speeds andadjustments. In operation, of course, the spring forces of the governorexactly balance the centrifugal force resultant in any position of thefly weights when the speed and load are unchanging and accordistics at agoverned speed of 2,000 R. P. M.,

whereas curves C and H indicate the same characteristics at 1,700 R. P.M. and 1,000 R. P. M., respectively. The centrifugal force resulta'ntsfor the same condition of the fly weights are represented by curves B, Dand F, the curves being taken at governed engine speeds of 2,000 R. P.M., 1,700 R. P. M., and 1,000 R. P. M., respectively.

It is of particular significance to note that the of the throttle valvesconform relatively closely with the curve of centrifugal forceresultants at unvarying speed. Thus, for example, the lower portion ofcurve A conforms very closely to the left-hand portion of thecorresponding curve B and it will be appreciated that the correspondenceof these two curves is even closer if the necessary increase of speed istaken into consideration. In short, the close correspondence of thesecurves illustrates the manner in which the present invention provides anideal condition in the range where frictional resistances are at aminimum and hunting or surging is avoidable On the other hand, from theincreasing divergency of the curves A and B adjacent their upper orrighthand portions, it will be evident that an increasing stabilizationfactor is automatically made available where an increased stabilizationis necessary. In other words, the present method of yieldablyresistingthe centrifugal forces operates to automatically vary thestabilization factor in accordance with the inherent demands of creasethe governed speed of the engine.

ingly determines the position of the throttle valve I6. Thus, it shouldbe noted that at full load speed of 1,700 R. P. M., as represented byspring force curve C and the associated curves D of centrifugal forceresultants, there is a relatively wide divergence in the curves as thespring tension increases. If the governor adjusted for such operation benow subjected to relative adjustment of the bell crank leverconstruction, the following change will occur: For example, as the setscrew 14 is tightened to move the lower arm 76 of the bell crankrelatively downwardly, an increased tension of the spring results to in-Without any material change, therefore, in the deflection rate of thespring since the effective rate remains substantially the same, thespring tension is increased for all relative positions of the parts.That is to say, for all angular positions .of the fly weights the springexerts substantially increased increments of resistance, whichincrements, it is particularly important to note, are substantiallyuniform.

For the next position of the foregoing, attention is respectfullydirected to a comparison of curves A and C, the former curverepresenting the characteristic action of the spring adjusted for agoverned speed of 2,000 R. P. M. from the former position of the partsrepresented by the curve C by tensioning of the auxiliary bell cranklever adjustment. It should be particularly noted that the springloading curve A is approximately parallel to the curve C. That is tosay, while the curve C diverges from the isochronous curve Bcorresponding to the same controlled speed of the engine, the curve Aquite closely approaches the corresponding isochronous curve B. Thusability to control the rate and characteristics of increase in springtension renders the in centrifugal'force curves, such as represented byrelative inclination of the curves B and D.

may be compensated in accordance with the present invention bycorrespondingly controlling the general inclination of the springloading characteristics at any speed. In short, by maintaining curve Aapproximately parallel to curve C while the curve of the isochronouscondition meanwhile shows an increase in rate of change, the finalfactors are brought into sufficiently close agreementrto assure animproved govemor Thus the maximum divergency of the upper part of curvesA and 13 represents less than control.

a per cent variation in speed from no-load to full-load.

It will be understoodby those skilled in the art that the foregoingcurves illustrate the manner in which the accuracy and stability ofgovernor action areunder precise'control by the present dual adjustment.Thus, for substantially arw desired governor speed, the springcharacteristics'are relatively adjustable to comply ,as precisely asdesirable to the isochronous condition forthat speed. Thus, for a speedof 1,700 B. P. M., the centrifugal force resultants and spring tensioncharacteristics may be brought into as close agreement as desire Theforegoing represents an important practical advantage of the presentinvention rendering the device adaptable to close and-accurate enginecontrol. Theimportant of this improvement will be understoo from aconsideration of curve H, Fig. 9, showing the characteristics of thespring which is 'now under consideration. With the forces imposed at theextreme free end thereof it'will be noted that this curve is a straightline having no desirable relation to the theoretically necessaryconditions for proper governor control.

I have found in general that the most accurate setting is obtained byemploying the greatest possible length of cantilever spring withithemaximum possible tensioning of the bell crank control. Any resultant.tendency to instability plied resultant centrifugal force wouldexperience an irregular variation at this point. According- 1y,byrestraining the fly weights for action within restricted limits,.centrifugal force resultants become so nearly identical to correspondingspring resistances that at some points in the range .of adjustment thegovernor performance may be for all practical purposes isochronous.

Attention is particularly drawn to the fact that in accordance with thepresent construction the fiyweights are pivoted about axes ofoscillation which are displaced outwardly a substantial distance in theaxis 'of rotation of the governor shaft 30. Invother words, the pivots50 about which the fiyweights oscillate are laterally spaced a distancebeyond the center of gravity of the flyweightsthroughout the path ofoscillation. This .Thusfcomparing this construction to, for example, aconstruction wherein the fiyweights shift through'a path such that theircentersof gravity extend substantiallybeyond the axis of oscillation, itwill be seen that a'sharp distincresulting from inordinate accuracy ofcontrol is then easily corrected by relaxing the tension of the bellcrank lever control and using the main adjustment to' stiffen, thespring. Accordingly,

. the present device-may be rapidly and efiiciently adjusted byrelatively un-skilled persons to give the highest possibledegree ofpracticalengine speed. control without such adverseficonditions 'knownas bucking, hunting or surging. Accord- .ingly, therefore, the presentgovernor'is of pracin accord tical importance in being adjustable ancewith each particular engine. It'is thought pertinent to further point inFig. 9 are not exactly straight lines, due to the fact thatthe'resultants as imposed on the spring are referred to the axis ofoscillatiomof the fly weights. The present invention contemplatesproportioning of the parts so that the centers of gravity ofthe flyweights are permitted ample y control movement without passingthe pointof maximum n omentthe characteristics of the apout that the curves ofcentrifugal force resultants shown 'tion exists. &Thus, in the lattercase, .the force curve tends to convexity inan upward direction whereaswith the present structure the force curve substantially coincides withthe spring characteristics. It will be obvious therefore that thepresent structure is ideally suited to making an accurate governor incombination with a canpoint when the control valve starts to move willbe at a speed approximating the no-load speed.

It will be apparent from the foregoing that the present inventionprovides a centrifugal governor which meets the demands of the art inthat it is capable of regulating the speed of an engineov-er a widerange of possible adjusted speeds while, at the same time, it is capableof adjustment of extraordinary accuracy in relation to any particularspeed. Heretofore governors materially sacrificed accuracy of control inorder to provide constructions capable of more than a; limited speedvariability. So, too, such devices have tended to become inordinatelybulky and space-consuming. The present invention provides a device whichmay be extremely compact and which permits the operator to vary thegovernor speed as desired.

It is thought that the invention and numerous of its'attendantadvantages will be understood from the foregoing description and it isobvious that numerous changes may be made in theform, construction andarrangement ofthe several parts without departing from the spirit orscope of the invention, or sacrificing any of its attendant advantages,the form herein described being; a preferred embodiment for the purposeof illustrating the invention.

The invention is hereby claimed as follows: 1.'A centrifugal governorcomprising centrifugal means adapted to rotate about a predeterminedaxis in response to engine speed, and including a flyweight shiftableabout an axis of oscillation toward and away from the said axis ofrotation, means to adjustably position a throttle valve comprising ayieldable, elongated spring member mounted on a support, means to imposethe centrifugal force resultants about said 7 axis of oscillation uponthe yieldable member comprising a crank means disposed in lateralcontacting relation with said spring and shiftable by said forceresultants in a path laterally of the spring to progressively deflectthe spring, said axis of oscillation being located outside the center ofgravity of the fiyweight throughout its operative path of movement. v

2. A centrifugal governor comprising centrifu gal means adapted torotate about a predetermined axis in response to engine speed, andincluding aflyweight shiftable about an axis'of oscillation toward andaway from the said axis of rotation, means "to adjustably position a 3.In a centrifugal governor comprising centrifugal means adapted tooperate in response to engine speed, means to adjustably position acontrol member comprising a yieldable elongated spring fixedly supportedat one end and means to impose the centrifugal force resultants of saidcentrifugal means upon the yieldable spring comprising spring impingingmeans movable alon the lateral face of said spring in lateral contactingrelationship and shiftable by said force resultants gressively laterallydeflect the spring while ex.- tending longitudinally of the springtoward the point of support whereby said centrifugal force resultantsare applied to the spring at a point progressively approaching thespring support with an increase in said resultants.

4. In acentrifugal governor comprising cenin a predetermined pathextending transversely of the spring in a direction to pro-- springmember mounted on a support. means to impose the centrifugal forceresultants of said centrifugal means upon the yieldable membercomprising a crank means disposed in lateral contacting relation withsaid spring and shiftable by said force resultants in a path laterallyof the spring to progressively deflect the spring laterally and-to movelongitudinally thereof, the parts being positioned and arranged so thatthe point of contact with the spring approaches the spring support withan increase in centrifugal force resultants, and means for adjusting thegoverning speed of said governor assembly comprising.

means for relatively adjusting thecrank and spring tovary the springresistance in substantially equal amountsthroughout the .path ofoperation of said crank means; I l

6. In acentrifugal sxgovemoncomprisingvcentrifugal means adapted to.operate in responsecto engine -speed mean'syrtoiz adjustably position. athrottle valve comprising a yieldable, elongated 4 spring member mountedon iaisupport meansiito impose the centrifugal-force resultants of saidcentrifugal means upon"- the yi'eliiable ime'mberl comprising 1 a cra nkmeans disposed in lateral contacting-"relation with said spring andshiftable by sa-id force resultant'svlnai:path:-laterallytrifugal meansadapted to operate in response to engine speed, means to adjustablyposition a throttle valve comprising a yieldable, elongated springmember mounted on a support, means to impose the centrifugal forceresultants of said centrifugal means upon the yieldable membercomprising a crank means disposed in lateral contacting relation withsaid spring and shiftable by said force resultants in apathlatetally-ofthe spring to progressively deflect the spring laterallyand to move longitudinally thereof, the parts being positioned andarranged so that the point of contact with the spring approaches thespring support with an increase in centrifugal force resultants, andmeans for adjusting the governing speed of said governor assemblycomprising means for relatively angularly adjusting the crank means. a

5. In a centrifugal governor comprising centrifugal'means adapted tooperate in response to engine speed, -means to adjustably position athrottle valve comprising a yieldable, elongated of the spring toprogressivelydeflect the spring laterally-and' to move longitudinallythereofg'the parts'being positioned and arranged so thatthe point ofcontact with the' spring approaches the spring support with'an increasein centrifugal force resultants, means for adjusting the governing speedof said governor assembly comprising means for relatively adjusting thecrank and spring to vary the spring resistance in substantially equalamounts throughout the path of operation of said crank means, andauxiliary means for providing a multi-speed governor control' comprisingmeans for varying the length of the yieldable spring with respect to thespring support.

'7. In a centrifugal governor comprising centrifugalmeans adapted tooperate in response to engine speed, means to adjustably position athrottle valve comprising a yieldable, elongated spring member mountedon a support, means to impose the centrifugal force resultants of saidcentrifugal means upon the yieldable member comprising a crank meansdisposed in lateral contacting relation with said spring and shiftableby said force resultants in a path laterally of the spring toprogressively deflect the spring laterally and to move longitudinallythereof, the parts being positioned and arranged so that the point ofcontact with the spring approaches the spring support with an increasein centrifugal force, said crank means being operatively shiftablethrough a predetermined angular range by application of said centrifugalforce resultants, and means for angularly varying the relativeangularlocation of said angular range of action and operative to predeterminethe governed speed of an associated engine.

8. In a centrifugal governor comprising centrifugal means adapted tooperate in response to engine speed, means to adjustably position athrottle valve comprising a yieldable, elongated spring member mountedon a support, means to impose the centrifugal force resultants of saidcentrifugal means upon the yieldable member comprising a crank meansdisposed in lateral contacting relation with said spring and shiftableby said force resultants in a path laterally of thespring toprogressively deflect the, spring laterally and to move longitudinallythereof, the parts being positionedand arranged so that the point ofcontact with the spring approaches the spring support with an increasein centrifugal force, said crank means being operatively shiftablethrough a predetermined angular range by applicentrifugal means upon theyieldable member comprising a crank means shiftable by said forceresultants and having an outer portion adapted cation of saidcentrifugal force resultants, and

means for angularly varying the relative angular location of saidangular range of action and operative to predetermlne the governed speedof an associated engine, said last-named means comprising an adjustablebell crank control adjustk able for determining the relative angulardisposi- I tion of the arms of the bell crank.

9. In a centrifugal governor comprising cen trifugal means adapted tooperate in response to engine speed, means to adjustably position athrottle valve comprising a yieldable, elongated spring membermounted ona support, means to impose the centrifugal force resultants ofgsaidcentriflmal means upon the yieldable member I comprising a crank meansdisposed inlateral contacting relation with said spring and shiftable bysaid force resultants in a path laterally of the spring to progressivelydeflect the spring laterally and to move'longitudinally thereof, theparts being positioned and arranged so that the P int of,

contact with the spring approaches the spring support with an increasein centrifugal force, said crank means being operatively shiftablethrough a predetermined angular range by application of said centrifugalforce resultants, and means for angularly varying the relative angularlocation of said angular range of action and operative to predeterminethe governed speed of an associated engine, said last-named meanscomprising means for applying said centrifugal force resultants forrotating said crank means, and means for vary-' ing the angular relationbetween the point of application of said centrifugal force resultantsand the crank means.

10. In a centrifugal governor comprising centrifugal means adapted tooperate in response to engine speed, means to adjustably position athrottle valve comprising a yieldable, elongated spring member mountedon a support, means to impose the centrifugal force resultants of saidcentrifugal means-upon the yieldable member comprising a crank meansshiftable by said force resultants and having an outer portion adaptedto progressively deflect the spring laterally and to move longitudinallythereof, the parts being positioned and arranged so that the point ofcontact with the spring approaches ,the spring support with an increasein centrifugal force, said crank means being operatively shiftablethrough a predetermined angular range by application of said centrifugalforce resultants, means for angularly varying the relative angularlocation of said angular range of action and operative to predeterminethe governed speed of an associated rotating said crank means, means forvarying the engine, said last-named means comprising means for. applyingsaid centrifugal force resultants for rotating said crank means, meansfor varying the angular relation between the point of application ofsaid centrifugalforce resultants and the crank means, and additionalmeans for adjusting the governor speed comprising means for varying thelength of said spring with respectto said support.

11. In a centrifugal governor comprising centrifugal means adapted to'operate in response to engine speed, means to adjustably position a 1throttle valve comprising a yieldable, elongated spring member mountedon a support, means to impose the centrifugal force resultants of saidto progressively deflect the spring laterally and to move longitudinallythereof, the parts being positioned and arranged so that the point ofcontact with the spring approaches the spring support with an increasein centrifugal force, said crank means being operatively shiftablethrough a predetermined angular range by application of said centrifugalforce resultants, means for angularly varying the relative angularlocation of said ang ilar range of action and operative to predeterminethe governed speed of an associated engine, said last-named meanscomprising means for applying said centrifugal force resultants forangular relation between the point of application of said centrifugalforce resultants and the crank means, and additional means for adjustingthe governor speed comprising a spring support longitudinally movablewith respect to the spring for varying the effective length thereof.

12. In acentrifugal governor comprising cen.-' trifugal means adapted tooperate in response to engine speed and including a flyweight, pivotmeans mounting said flyweight for movement toward and away from the axisof rotation of said centrifugal means, said pivot being located radiallyoutwardly beyond the center of gravity of said ilyweight throughout itspath of movement, means to adjustably position a control membercomprising a yieldable elongated spring supported atone end and means toimpose the centrifugal force resultants at said pivot upon the yieldablespring comprising spring impinging means movable along the lateral faceof said spring in lateral contacting relationship and shiftable by/saidforce resultants in a predeter:

mined path extending transversely of the spring in a direction toprogressively laterally defiect the spring while extendinglongitudinally of the spring toward the point of support whereby saidcentrifugal force resultants are applied to the spring at a pointprogressively approaching the spring support with an increase in saidresultants.

13. In a centrifugal governor comprising centrifugal means adapted tooperate in response to engine speed, means toadjustably position acontrol member comprising a yieldable elongated spring supported at oneend and means to impose the centrifugal force resultants of said cenv tosaid centrifugal means in said path of the spring impinging meanswhereby to vary the spring tension applied to said spring impingingmember in substantially equal amounts throughout said path of movement.I

14. In a centrifugal governor comprising centrifugal means adapted tooperate in response to engine speed, means to adjustably position acontrol member comprising a yieldable elongated spring supported at oneend and means to impose by said centrifugal force resultants are appliedto the spring at a point progressively approaching the spring supportwith an increase in sald resultants, said spring bein supported at saidone end in a line extending inwardly of said spring impinging means innormal position whereby to set upan initial predetermined springresistance.

ADDISON C. HOOF.

